1. Field of Invention
The present invention relates, generally, to engine valvetrain systems and, more specifically, to a locator for use in a valvetrain of a cylinder head of an internal combustion engine.
2. Description of the Related Art
Conventional engine valvetrain systems known in the art typically include one or more camshafts in rotational communication with a crankshaft supported in a block, one or more intake and exhaust valves supported in a cylinder head, and one or more intermediate members for translating radial movement from the camshaft into linear movement of the valves. The valves are used to regulate the flow of gasses in and out of cylinders of the block. To that end, the valves have a head and a stem extending therefrom. The valve head is configured to periodically seal against the cylinder head. The valve stem is engaged by the intermediate member so as to open and close the valve as the camshaft rotates.
The valve stem is typically supported by a valve guide that is operatively attached to the cylinder head. The stem extends through the valve guide and travels therealong in response to engagement from the intermediate member. To seal the valve head against the cylinder head, a compression spring is disposed about the valve stem in the cylinder head. The spring has a bottom and a top. The bottom of the spring engages a valve seat which, in turn, engages the cylinder head adjacent the valve guide. The valve seat is frequently manufactured from a material that is harder than that of the cylinder head and/or valve guide, so as to decrease engine wear. The top of the spring engages a retainer that is operatively attached to the valve stem. The spring is movable between two different compressed positions, commonly referred to as “valve open” and “valve closed”. In the valve closed position, potential energy from the loaded spring holds the valve head sealed against the cylinder head. In the valve opened position, rotation from the camshaft translates linear movement to the valve stem via the intermediate member, which compresses the spring and un-seals the valve head from the cylinder head, thereby allowing gasses to flow into the cylinder of the block.
Typically, the valve, valve guide, seat, and spring are concentrically aligned with each other so as to promote even loading to the valve stem. In operation, and particularly at high engine rotational speeds, the spring may rotate and/or move out of concentricity with the valve stem, leading to uneven loading. Such movement of the valve spring is detrimental to engine performance, as uneven loading may result in high-speed “valve float,” whereby the spring is consequently unable to properly seal the valve head against the cylinder head. Moreover, as the spring moves, it may wear against or otherwise engage other valvetrain components, such as parts of the cylinder head, the valve guide, etc., which leads to decreased engine life.
Each of the components of an engine valvetrain system of the type described above must cooperate to effectively translate movement from the camshaft so as to operate the valves properly at a variety of engine rotational speeds. In addition, each of the components must be designed not only to facilitate improved performance and efficiency, but also so as to reduce the cost and complexity of manufacturing and assembling the valvetrain system, as well as reduce wear in operation. While engine valvetrain systems known in the related art have generally performed well for their intended purpose, there remains a need in the art for an engine valvetrain system that has superior operational characteristics, and, at the same time, reduces the cost and complexity of manufacturing the components of the system.